1. Field of the Invention
This invention relates generally to removable tire traction devices.
2. Description of the Prior Art
Various devices have been proposed as a substitute for tire chains in providing temporary additional traction in very adverse road conditions. In general terms, the majority of prior traction devices consist of a pair of metal cleats which fit closely on opposite sides of the periphery of a tire, and are clamped or bolted together over the outside of the wheel. Such traction devices are primarily intended for short term emergency use, such as where a car is stuck in a snowdrift or in deep mud. These devices must be portable to allow them to be carried in the car for such emergencies.
The known prior emergency traction devices generally require relatively complex procedures to attach and detach the traction cleats. Often, these procedures involve bolting portions of the devices together, attaching springs, or making size adjustments. These operations are difficult when performed under adverse weather conditions, especially when working within the cramped spaces in the rear wheel well. Some prior devices have not been adapted to allow adjustment to wheels of differing diameters, or have utilized springs in an effort to make one size of traction device fit wheels of several sizes. Many of these devices are unstable once the wheel is in motion because the cleats or "shoes" which fit around the tires are not firmly connected together. A loose connection allows the cleats to move back and forth with respect to one another, causing wear on the tire and vibration, as well as potentially allowing the cleats to twist and break loose from the tire. This problem is particularly serious where springs are utilized to hold the cleats in place on the tire, since dirt or other material getting between the cleat and the tire may extend the springs sufficiently to dislodge the cleat from the tire.